Systems and methods for selectively stimulating components in, on, or near the pudendal nerve or its branches to achieve selective physiologic responses

ABSTRACT

Systems and methods selectively stimulate components of the pudendal nerve away from the sacral root to evoke desired physiologic responses in persons who lack the ability to otherwise produce these responses—e.g., maintain continence and/or produce micturition, and/or provide male/female sexuality responses, and/or provide bowel responses. The systems and methods use a multiple electrode array, or individual electrodes, placed on, in, or near the pudendal nerve. The electrode array, or individual electrodes, in association with a pulse generator, provide selective stimulation of individual fascicles within the pudendal nerve, to achieve different physiologic responses.

RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 60/280,222, filed Mar. 30, 2001, and entitled“Systems and Methods for Selectively Stimulating Fascicles in thePudendal Nerve to Achieve Selective Physiologic Responses,” which isincorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to systems and methods for stimulating nerves inanimals, including humans.

BACKGROUND OF THE INVENTION

The lower urinary tract comprises the bladder, urethra, periurethralmuscles and sphincters, and accessory organs. The lower urinary tracthas two primary functions: the accumulation and storage of urine(continence), and the elimination of urine at an appropriate time(micturition or urination).

In able-bodied individuals, continence is maintained by low-pressureurine storage in a highly compliant bladder, augmented by tonic activityin the internal and external urethral sphincters. Micturition isachieved in such individuals by synergic relaxation of the urethralsphincter and contraction of the bladder.

Supra-sacral spinal cord injury, brainstem stroke, or disease (e.g.,multiple sclerosis) can break or otherwise disrupt the path or paths bywhich electrical signals generated by the brain normally travel toneuromuscular groups in the lower urinary tract and elsewhere in thebody. As a result, even though these nerves and muscles are intact,abnormal electrical signals or no electrical signals are received fromthe spinal cord, and the associated muscles do not function.

In the lower urinary tract, paralysis of the bladder may occur, and,with it, the inability to empty the bladder voluntarily. Loss of bladdercontrol is a major, devastating effect of these conditions.

These conditions can also result in bladder hyper-reflexia, in which thebladder contracts spontaneously at small fluid volumes. Bladdersphincter dysynergia can also occur, in which the external urethralsphincter contracts, rather than relaxes, during bladder contractions.Hyper-reflexia and dysynergia lead to bladder contraction with highpressure, impaired voiding, large post-void residual volumes, and lowbladder compliance.

These dysfunctions often lead to ureteric reflux and obstruction,infection of the kidneys, episodes of autonomic dysreflexia withdangerous rises in blood pressure, incontinence that leads to skinproblems, frequent urinary tract infections, and long term renal damage.Urological complications are one of the leading causes of morbidity inpersons with spinal cord injury. Loss of bladder control also hasprofound social impact and leads to decreased quality of life. It alsoleads to large direct medical costs of procedures, supplies, andmedications.

Clean self-catheterization, sometimes in combination withanticholinergic agents, is presently the most effective way to treat theneurogenic bladder. This treatment, however, requires individuals withdexterity for catheterization, as well as tolerance for and response tothe anticholinergic agents. Even with these individuals, urinary tractinfections persist.

Restoration of bladder evacuation and continence has been achieved byelectrical stimulation of the sacral nerve roots, coupled with surgicaltransections of sacral sensory nerve roots (dorsal rhizotomy). Thedorsal rhizotomy eliminates bladder hyper-reflexia and bladder-sphincterdysynergia. This technology has resulted in documented medical, qualityof life, and financial benefits. However, widespread application of thistechnology is limited because of the irreversible effects of the dorsalrhizotomy (which leads to loss of reflex erection in males) and thecomplex surgical implant procedure itself (which requires access throughthe back along the spine, laminectomies of vertebral bodies, and therisk of cerebrospinal fluid leaks and intradural infections).

Other, physical conditions also have adverse affects on day-to-daybladder function. For example, a condition called urge incontinence, forwhich there is sometimes no neurological cause found, results in ahyperactive bladder and a loss of continence. There is also a conditioncalled stress incontinence, which can arise after muscle is stretched inthe pelvis during childbirth. Bladder instability or dysfunction arealso chronic conditions of many elderly people, especially women.

There is a need for systems and methods that can restore bladder andother urinary tract functions, e.g., micturition and/or continence, in astraightforward manner, without requiring self-catheterization, drugtherapy, complicated surgical procedures, or irreversible surgicaltransections of nerve fibers. There is also a need for systems andmethods that address dysfunctions or injuries affecting lower bowelfunctions (e.g., fecal incontinence and/or defecation) and/or sexualfunctions (e.g., erection of the penis, vaginal lubrication,ejaculation, and/or orgasm).

SUMMARY OF THE INVENTION

The invention provides systems and methods for stimulating selectivelythe components or fascicles of a mixed or compound nerve, to monitor, orcontrol, or both monitor and control desired physiological functions.Selectivity among nerve components can include the selection among thecomponents within a compound nerve trunk, or among branches of a nervetrunk, or between afferent (sensory) or efferent (motor) nerve fiberswith a given nerve structure, or selection with regard to size of nervefibers, or with regard to direction of activation, or with regard to thefunctions of nerve activation (resulting in the generation of an actionpotential or impulse and its propagation along a nerve) or nerveinactivation or block (resulting in prevention of activation orpropagation of an action potential or impulse).

The systems and methods that embody features of the invention aregenerally applicable for use in conjunction with mixed or compound nervestructures throughout the body. For example, the systems and methods arewell suited for use in conjunction with the pudendal nerve, and, inparticular, the pudendal nerve trunk and its afferent and efferentbranches or components away from the sacral root, that innervate musclesand organs in the lower urinary tract, lower bowel, and the genitals.The pudendal nerve trunk or its branches are spaced away from the sacralroot and spinal column. They are accessible from the front of the bodyand do not require complicated surgical procedures on, in, or near thespinal column or entailing dorsal rhizotomy.

One aspect of the invention provides systems and methods for controllinga desired physiological function that involve placing at least oneelectrode on, in, or near a targeted component of the pudendal nerveaway from a sacral root. The systems and methods apply an electricalsignal to the electrode to stimulate selectively the targeted component,thereby affecting the desired physiological function.

The desired physiological function can vary. It can, for example,comprise controlling a lower urinary tract function, such as urinaryincontinence or micturition, or both. As another example, the desiredphysiological function can comprise controlling a lower bowel function,such as fecal incontinence, or defecation, or peristalsis, orcombinations thereof. As another example, the desired physiologicalfunction can comprise controlling a sexual function, such as erection,vaginal lubrication, ejaculation, or orgasm, or combinations thereof.

The systems and methods can achieve the desired physiological result bythe selective stimulation of an afferent component of the pudendalnerve, or an efferent component of the pudendal nerve, or both, using asingle electrode or a multiple electrode array. The selectivestimulation can serve to activate selectively one or more components, oractivate selectively one component while inactivating selectivelyanother component, or inactivate selectively one or more components, orother combinations of activation and/or inactivation, to achieve thedesired physiological result.

For example, the systems and methods can place the electrode on, in, ornear a pudendal nerve branch, which can comprise, depending upon thedesired function, either an afferent nerve branch, an efferent nervebranch, or both. In this arrangement, the electrode can comprise asingle electrode or a multiple electrode array. The single electrode orthe electrode array can be used in association with a pulse generator,to provide selective stimulation of the pudendal nerve branch, toachieve a desired physiological response.

Alternatively, or in combination, the systems and methods can place theelectrode on, in, or near the pudendal nerve trunk. In this arrangement,the systems and methods can apply an electrical signal or signals tostimulate selectively an afferent component of the pudendal nerve trunk,or an efferent component of the pudendal nerve trunk, or both. In thisarrangement, the electrode can comprise a multiple electrode arrayoperated to achieve selective stimulation of targeted afferentcomponent(s), or targeted efferent component(s), or both. The electrodearray can be used in association with a pulse generator, to provideselective stimulation of individual components or fascicles within thepudendal nerve trunk, to achieve different physiological responses.

The systems and methods can apply the electrical signal(s)in response toa volitional act of an individual, or in response to sensedphysiological events, or both. The systems and methods can also apply apre-programmed pattern of electrical signals, either on demand or inresponse to sensed physiological events. The physiological events can besensed by the placement of at least one recording electrode in, on, ornear a nerve, e.g., the pudendal nerve trunk or a branch or component ofthe pudendal nerve.

This aspect of the invention provides systems and methods involving thepudendal nerve, which are capable of evoking desirable physiologicalresponses in persons who lack the ability to otherwise produce theseresponses—e.g., maintain urinary continence and/or produce micturition,and/or maintain fecal incontinence and/or produce defecation, and/ormaintain normal male/female sexuality responses.

For example, a micturition response (increase in bladder pressure andreduction in activity in the external urethral sphincter) can be evokedby selective stimulation of a urethral afferent component of thepudendal nerve (e.g., to cause bladder contractions, or affect voluntaryurinary sphincter function, or both), an efferent component of thepudendal nerve (e.g., to affect voluntary urinary sphincter function),or both. For a micturition response, selective stimulation of anefferent component can be undertaken to affect nerve inactivation,causing relaxation of the urinary sphincter, thereby facilitatingmicturition. This may undertaken alone or be combined with selectivestimulation of an afferent component to affect nerve activation, causingbladder contraction, further promoting micturition. Selectivestimulation of an afferent component alone to affect nerve activation,causing bladder contraction, can also promote micturition.

A continence response (arresting bladder contractions) can be evoked byselective stimulation of a genital afferent component of the pudendalnerve (to inhibit bladder contractions), an efferent component of thepudendal nerve (to affect nerve activation for voluntary urinarysphincter function), or both. For a continence response, selectivestimulation of either or both afferent or efferent components can beundertaken to affect nerve activation to evoke the desire physiologicalresponses.

As other examples, a defecation response (increase in contraction of therectum and reduction in activity in the external anal sphincter) can beevoked by selective stimulation of an afferent component of the pudendalnerve (to cause contractions of the rectum, or affect voluntary analsphincter function, or both), an efferent component of the pudendalnerve (to affect voluntary anal sphincter function), or both. For adefecation response, selective stimulation of an efferent component canbe undertaken to affect nerve inactivation, causing relaxation of theanal sphincter, thereby facilitating defecation. This may be undertakenalone or be combined with selective stimulation of an afferent componentto affect nerve activation, causing contraction of the rectum, furtherpromoting defecation. Selective stimulation of an afferent componentalone to affect nerve activation, causing contraction of the rectum, canalso promote defecation.

A fecal continence response (arresting contractions of the rectum andaffecting activity of the voluntary anal sphincter) can be evoked byselective stimulation of an afferent component of the pudendal nerve (toinhibit contractions of the rectum), an efferent component of thepudendal nerve (to affect voluntary anal sphincter function), or both.For a fecal continence response, selective stimulation of either or bothafferent or efferent components can be undertaken to affect nerveactivation to evoke the desire physiological responses.

A response for controlling peristalsis (contraction of the colon) can beevoked by selective stimulation of one or more afferent components ofthe pudendal nerve. For peristalsis, selective stimulation of either orboth afferent or efferent components can be undertaken to affect nerveactivation to evoke the desire physiological responses.

As other examples, an erection response in males or a vaginallubrication response in females may be evoked by the selectivestimulation of an afferent component of the pudendal nerve—alone or incombination with other afferent components of the nervous system (e.g.,ventral genital)—to affect dilation of blood vessels in the penis orlubrication in the vagina. An ejaculation response may be evoked by theselective stimulation of an afferent component of the pudendal nerve, oran efferent component of the pudendal nerve, or both—alone or incombination with other afferent components of the nervous system (e.g.,ventral genital) and/or other efferent components of the nervoussystem—to contract pelvic muscles and cause ejaculation. An orgasmresponse may be evoked by the selective stimulation of an afferentcomponent of the pudendal nerve—alone or in combination with otherafferent components (e.g., ventral genital) and other components of thecentral nervous system.

In all the above examples, stimulation can be evoked automatically, ormanually by a volitional act of the user. The stimulation can involvethe use of pre-programmed pattern of stimulation signals.

Another aspect of the invention provides systems and methods formonitoring function of the lower urinary tract, or the lower bowel, orboth. The systems and methods place at least one recording electrodesized and configured to be located on, in, or near a targeted componentof the pudendal nerve to sense electrical activity relating,respectively, to bladder function or lower bowel function. The systemsand methods generate an informational signal based upon the electricalactivity sensed by the recording electrode.

In the case of bladder function, the informational signal can relate,e.g., to bladder contraction, bladder volume, or onset of bladdercontraction. In the case of lower bowel function, the informationalsignal can relate, e.g., to contraction of the rectum, volume of therectum, or onset of contraction of the rectum.

The component targeted by the recording electrode can comprise anafferent component of the pudendal nerve, an efferent component of thepudendal nerve, or both.

In one arrangement, the systems and methods locate the recordingelectrode on, in, or near a targeted branch of the pudendal nerve. Thetargeted branch can be an afferent branch, an efferent branch, or both.

Alternatively, or in combination, the systems and methods place therecording electrode on, in, or near the pudendal nerve trunk. In thisarrangement, the component targeted by the recording electrode cancomprise an afferent component of the pudendal nerve trunk, an efferentcomponent of the pudendal nerve trunk, or both.

According to another aspect of the invention, the systems and methodsgenerate a control signal affecting, respectively, bladder function orlower bowel function based, at least in part, upon the informationalsignal generated. In the case of bladder function, the control signalcan either inhibit bladder contractions (evoking urinary continence) orcause bladder contraction (evoking micturition). In the case of lowerbowel function, the control signal can either inhibit lower bowelfunction (evoking fecal continence) or cause lower bowel function(evoking defecation).

In one arrangement, the control signal is applied to an electrodelocated on, in, or near a targeted component of the pudendal nerve, inthe manner already described.

For example, in the monitoring and control of bladder function, theonset of bladder contractions can be detected by recording electricalactivity in the pudendal nerve. When detected, the informational signalis generated, and stimulation of a genital afferent component of thepudendal nerve, an efferent component of the pudendal nerve, or both canoccur automatically, to arrest the contractions and affect function ofthe voluntary urethral sphincter. Alternatively, the user can manuallyinitiate the stimulation of a genital afferent component of the pudendalnerve, an efferent component of the pudendal nerve, or both to evokecontinence on demand. Likewise, the user can manually initiate thestimulation of a urethral afferent component of the pudendal nerve, anefferent component of the pudendal nerve, or both to evoke micturitionon demand.

For example, in the monitoring and control of lower bowel function, theonset of contractions in the rectum can be detected by recordingelectrical activity in the pudendal nerve. When detected, theinformational signal is generated, and stimulation of an afferentcomponent of the pudendal nerve, an efferent component of the pudendalnerve, or both can occur automatically, to arrest the contractions andaffect function of the voluntary anal sphincter. Alternatively, the usercan manually initiate the stimulation of an afferent component of thepudendal nerve, an efferent component of the pudendal nerve, or both toevoke fecal continence on demand. Likewise, the user can manuallyinitiate the stimulation of an afferent component of the pudendal nerve,an efferent component of the pudendal nerve, or both to evoke defecationon demand.

Other features and advantages of the inventions are set forth in thefollowing specification and attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of the lower urinary tract and the pudendalnerve that innervates the organs and muscles of the lower urinary tract;

FIG. 2 is a schematic cross sectional view of the pudendal nerve,showing the peripherally separated fascicles that occupy the main nervetrunk, comprising different efferent and afferent nerve branches;

FIG. 3 is an enlarged cross sectional view of the pudendal nerve, asshown in FIG. 2, in association with a multiple electrode cuff thatembodied features of the invention positioned about the pudendal nervetrunk;

FIG. 4 is a perspective side view of the pudendal nerve and multipleelectrode cuff shown in FIG. 3;

FIG. 5 is a schematic view of a system, which is coupled to the multipleelectrode cuff shown in FIGS. 3 and 4, and which provides selectivestimulation of individual fascicles within the pudendal nerve, toachieve different physiologic responses, e.g., continence andmicturition;

FIG. 6 is view of a manual controller that can be used in associationwith the system shown in FIG. 5, the manual controller including amicroprocessor that enables a user interface; and

FIG. 7 is a view of a portion of the user interface that the manuallycontroller shown in FIG. 6 can present to enable selection of differentphysiologic response using the system shown in FIG. 5.

The invention may be embodied in several forms without departing fromits spirit or essential characteristics. The scope of the invention isdefined in the appended claims, rather than in the specific descriptionpreceding them. All embodiments that fall within the meaning and rangeof equivalency of the claims are therefore intended to be embraced bythe claims.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The various aspects of the invention will be described in connectionwith achieving the detection of nerve activity within and/or stimulationof targeted nerve components or fascicles within complex or compoundnerve structures throughout the body. For the purpose of illustration,the invention will be disclosed in the context of the compound pudendalnerve trunk or its branches located away from the sacral root, toachieve desired physiological results in the lower urinary tract, and/orthe lower bowel, and/or genital regions. That is because the featuresand advantages that arise due to the invention are well suited to thispurpose. Still, it should be appreciated that the various aspects of theinvention can be applied elsewhere in the body to achieve otherobjectives as well.

I. Anatomy of the Compound Pudendal Nerve Trunk

The pudendal nerve trunk (PNT) carries afferent (sensory) and efferent(motor) nerve components that innervate muscles and organs in the lowerurinary tract. FIG. 1 shows, in schematic form, the major branches ofthe pudendal nerve trunk (PNT). These major branches comprise theprincipal sensory (afferent) branch (SB) and the principal motor(efferent) branch (MB).

Extending from the principal sensory branch are the genital sensorybranch (GSB) and the urethral sensory branch (USB). The genital sensorybranch (GSB) comprises the dorsal nerve of the penis in males and theclitoral nerve in females. The urethral sensory branch (USB) innervatesthe urethra.

Extending from the principal motor branch are the external urethralsphincter branch (UMB), which innervates the external urethralsphincter, and the external anal sphincter branch (AMB), whichinnervates the external anal sphincter.

Research has indicated that the electrical activity of the pudendalnerve is modulated during bladder contractions. Thus electrical activityof the pudendal nerve can be used to detect the onset of bladdercontractions. As just explained, the pudendal nerve innervates themuscles of the pelvic floor, including the external (voluntary) urethralsphincter and the external (voluntary) anal sphincter. In humans,increases in bladder pressure evoked by rapid injections of fluid intothe bladder evoke an increase in activity of muscles of the pelvicfloor. Following spinal injury, bladder-sphincter dysynergia leads toincreases in pelvic floor bladder contractions. These data indicate thatelectrical recording of activity in the pudendal nerve or its brancheswill detect reflexive bladder contractions.

Research has also shown that electrical stimulation of the genitalsensory branch (GSB) of the pudendal nerve inhibits bladdercontractions. These data indicate that electrical stimulation of the GSBcan abolish hyper-reflexive bladder contractions and increase bladdercapacity in individuals with bladder hyper-reflexia due, e.g., to spinalinjury.

Traditional views hold that coordinated micturition (bladdercontractions coupled with a reduction in activity of the externalurethral sphincter) requires a spinal-brainstem-spinal reflex loop thatis triggered by bladder distension. However, bladder contractions canalso be evoked by activation of urethral afferents. The data indicatesthat stimulation of the urethral sensory nerve branch (USB) will evoke amicturition-like bladder contraction and a reduction in activity in theurethral sphincter. This combination will lead to low-pressurecontinuous stream evacuation of the bladder on demand.

A cross section of the pudendal nerve trunk (PNT) (see FIG. 2) showsthat the major motor and sensory nerve branches just described arelocated in peripherally spaced-apart components or fascicles in thenerve trunk (PNT). This nerve geometry lends itself to the use of aperipherally spaced cuff array 16 of electrodes 18, 20, 22, 24 (seeFIGS. 3 and 4) implanted in, on, or near the pudendal nerve trunk (PNT)to affect independent neural sensing and/or neural stimulation of thenerve fascicles of the pudendal nerve trunk (PNT).

FIGS. 3 and 4 show the array 16 as comprising four electrodes 18, 20,22, and 24 spaced apart at regular ninety-degree intervals. In theillustrated embodiment, the array 16 also includes two ring returnelectrodes R1 and R2 at each end of the cuff. The array 16 can comprisea greater or lesser number of electrodes 18, 20, 22, and 24, and thespacing among the electrodes 18, 20, 22, and 24 can differ and need notbe uniform.

The array 16 is desirably implanted without prior reference to theparticular fascicular structure of the nerve, leading to a randomorientation between electrodes and fascicles. Thus, programming or“tuning” will be required by a clinician to ascertain positions andoperating parameters of electrodes 18 to 24 in the array 16 to bringabout the desired stimulation of individual targeted fascicles. Furtherdetails of the programming or “tuning,” of the array 16 prior to usewill be described in greater detail later. Alternatively, separateelectrodes could be implanted in, on, or near the individual branches,thereby avoiding a random orientation. Techniques enablingsub-fascicular selection could also be employed.

II. System Overview

FIG. 5 shows a system 10 that makes possible the detection of neuralimpulses and/or the stimulation of targeted nerve branches within thecompound pudendal nerve trunk (PNT).

The system 10 can generate and distribute electrical stimulus waveformsto selected afferent and/or efferent nerve fascicles in the nerve trunk(PNT), or to selected afferent and/or efferent branches outside thenerve trunk (PNT).

As shown, the system 10 comprises four basic functional componentsincluding (i) one or more control signal sources 12; (ii) a pulsegenerator 14; (iii) at least one electrode 18; and (iv) electrical leads26 that couple the electrode 18 to the pulse generator 14.

As assembled and arranged in FIG. 5, the control signal sources 12function to generate prescribed response demand inputs to the pulsegenerator 14. The prescribed demand inputs are associated with desiredphysiologic response(s), as will be described in greater detail later.

The pulse generator 14 may include an on-board, programmablemicroprocessor 30, which carries embedded code. The code expressespre-programmed rules or algorithms under which the desired electricalstimulation waveform is generated and distributed to the electrode array16 in response to the prescribed demand inputs. According to theseprogrammed rules, the pulse generator 14 directs prescribed stimulationwaveforms through the leads 26 to the electrode 18 or electrodes 18 to24 in the electrode array 16 that stimulate selectively the targetedfascicle associated with the desired response. The electrode selectionparameters and operating parameters for a given demand input arepreprogrammed into the code by a clinician, as will be described later.In this way, the particular physiologic response associated with aparticular prescribed demand input is reliably achieved.

The stimulation waveform generated is desirable low frequency, e.g.,less than about 10 Hz. The frequency can be tuned to achieve the desiredphysiological result. The shape of the waveform can also vary. It can,e.g., be a typical square pulse, or possess a ramped shape. The pulse,or the rising or falling edges of the pulse, can present various linear,exponential, hyperbolic, or quasi-trapezoidal shapes. As will bedescribed later, the stimulation waveform can be continuous, or it canbe variable and change cyclically or in step fashion in magnitude andwaveform over time.

As thus described, the system 10 is operable for controlling aphysiological function. The system 10 includes at least one electrode 18sized and configured to be located on, in, or near a targeted componentof the pudendal nerve away from a sacral root. The pulse generator 14coupled to the electrode applies an electrical signal to stimulateselectively the targeted component of the pudendal nerve, to achieve thedesired physiologic function.

The targeted component can comprise an afferent component of thepudendal nerve, or an efferent component of the pudendal nerve, or both.As shown in FIG. 5, the electrode takes the form of a multiple electrodearray 16 that is sized to be located on, in, or near the pudendal nervetrunk (PNT). In this arrangement, as will be described in greater detaillater, the pulse generator 14 is able to stimulate selectively anafferent component in the nerve trunk, or an efferent component in thenerve trunk, or both, to achieve the desired physiological function.

Alternatively, a single electrode 18 or an array of electrodes 18 to 24like that shown in FIG. 5 can be sized and configured to be located on,in, or near a pudendal nerve branch, outside the nerve trunk. The nervebranch can comprise an afferent branch, or efferent branch, or both. Inthis arrangement, the pulse generator 14 is able to stimulateselectively an afferent branch of the nerve trunk, or efferent branch ofthe nerve trunk, or both, to achieve the desired physiological function.

As will be described in greater detail later, the pulse generator 14 canbe operated to apply the electrical signal(s) in response to avolitional act of an individual. Due to the microprocessor 30, the pulsegenerator 14 can be, if desired, operated to apply a pre-programmedpattern of electrical signals.

The system 10 can also include at least one recording electrode locatedin, on, or near a nerve to sense electrical events. As illustrated, theelectrode serves to detect electrical activity within the pudendal nervetrunk (PNT), and, in particular, within the efferent external analsphincter branch (AMB) and/or efferent urethral sphincter branch (UMB)of the pudendal nerve trunk (PNT). This electrical activity can becorrelated with the onset of bladder contractions and/or contractions ofthe rectum. In this arrangement, the pulse generator 14 can be coupledto the recording electrode and operated to apply the electrical signalin response to the sensed electrical events.

The system 10 can be configured and operated in association with thepudendal nerve trunk or its branches to achieve various desiredphysiological functions. The system 10 can, for example, be configuredand operated to control one or more lower urinary tract functions, suchas urinary incontinence, and/or micturition, or both. As anotherexample, the system 10 can be configured and operated to control one ormore lower bowel functions, such as fecal incontinence, and/ordefecation, or peristalsis, or combinations thereof. As yet anotherexample, the system 10 can be configured and operated to control one ormore sexual functions, such as (in males) erection, and/or ejaculation,and/or orgasm, or (in females) vaginal lubrication and/or orgasm.

The configuration and operation of the system 10 to achieve thesevarious physiological functions will now be described in greater detail.

III. Lower Urinary Tract Functions

The system 10 can generate and distribute stimulus waveforms to thefascicle of the afferent genital sensory branch (GSB) of the pudendalnerve trunk (PNT), or the fascicle of the urethral efferent branch(UMB), or both. The stimulation of the afferent component inhibitsbladder contractions. The stimulation of the efferent component affectsvoluntary urinary sphincter function. Alone, or in tandem, thestimulation can serve to arrests bladder contractions (including thoseof a nascent hyper-reflexive type), and/or affect urinary sphincterfunction. The system 10 can thereby control urinary continence.

The system 10 can also generate and distribute electrical stimuluswaveforms to the fascicle of the afferent urethral sensory branch (USB)of the pudendal nerve trunk (PNT), or the fascicle of the urethralefferent branch (UMB), or both. The stimulation of the afferentcomponent produces bladder evacuation. The stimulation of the efferentcomponent affects voluntary urinary sphincter function. Alone, or intandem, the stimulation can achieve micturition on demand.

In the illustrated embodiment, neural recording and stimulation arecarried out by the array of multiple, circumferentially spacedelectrodes 18 to 24 placed near, on, or in the pudendal nerve trunk(PNT), shown in FIGS. 3 and 4. Of course, individual electrodes ormultiple electrode arrays located in, on or near the genital afferentbranch (GSB) and/or the urethral afferent branch (USB) and/or urethralefferent branch (UMB) could be used.

According to pre-programmed rules expressed by the code embedded in themicroprocessor 30, the pulse generator 14 directs prescribed stimulationwaveforms through the leads 26 to the electrode 18 or electrodes 18 to24 in the array 16 that stimulate the targeted fascicle associated withthe desired response, e.g., the afferent genital sensory branch (GSB)and/or the efferent urethral branch (UMB) (for continence) or theafferent urethral sensory branch (USB) and/or the efferent urethralbranch (UMB) (for micturition).

A continence response (arresting bladder contractions) can be evoked byselective stimulation of a genital afferent component of the pudendalnerve (to inhibit bladder contractions), an efferent component of thepudendal nerve (to affect nerve activation for voluntary urinarysphincter function), or both. For a continence response, selectivestimulation of either or both afferent or efferent components can beundertaken to affect nerve activation to evoke the desire physiologicalresponses.

The microprocessor code can also express rules or algorithmspre-programmed by a clinician, under which electroneurogram (ENG)activity in the whole pudendal nerve trunk (PNT), or the individualefferent external anal sphincter branch (AMB) and/or efferent urethralsphincter branch (UMB) of the nerve trunk (PNT), are characterized togenerate an information signal. The informational signal can relate,e.g., to bladder contraction, or bladder volume, or onset of bladdercontraction. The informational signal can be expressed in auser-readable output, to provide feedback to the user or clinician as tothe state of bladder function. As will be described later, theinformational signal can also be used as a control, to lead to theautomatic generation of a demand input.

In the illustrated implementation, the pulse generator 14 is programmedto respond to one or more prescribed continence demand inputs to affect,e.g., an arrest of nascent hyper-reflexive bladder contractions (therebyachieving continence). In response to the one or more prescribedcontinence demand inputs, the pulse generator 14 applies electricalwaveforms to the electrode 18 or electrodes 18 to 24 in the array 16that are positioned to stimulate the afferent genital sensory branch(GSB) and/or the efferent urethral motor branch (UMB) of the pudendalnerve trunk (PNT).

In the illustrated embodiment, the pulse generator 14 is also programmedto respond to one or more prescribed micturition demand inputs to affectbladder evacuation (thereby achieving micturition). In response to theone or more prescribed micturition demand inputs, the pulse generator 14applies electrical waveforms to the electrode 18 or electrodes 18 to 24in the array 16 that are positioned to stimulate the afferent urethralsensory branch (USB) and/or the efferent urethral motor branch (UMB) ofthe pudendal nerve trunk (PNT).

A micturition response (increase in bladder pressure and reduction inactivity in the external urethral sphincter) can be evoked by selectivestimulation of a urethral afferent component of the pudendal nerve(e.g., to cause bladder contractions, or affect voluntary urinarysphincter function, or both), an efferent component of the pudendalnerve (e.g., to affect voluntary urinary sphincter function), or both.For a micturition response, selective stimulation of an efferentcomponent can be undertaken to affect nerve inactivation, causingrelaxation of the urinary sphincter, thereby facilitating micturition.This may undertaken alone or be combined with selective stimulation ofan afferent component to affect nerve activation, causing bladdercontraction, further promoting micturition. Selective stimulation of anafferent component alone to affect nerve activation, causing bladdercontraction, can also promote micturition.

A given control signal source 12 can be configured to generate thedemand inputs automatically, without volitional act by the user. A givencontrol signal source 12 can also be configured to generate the demandinputs manually, thereby requiring a volitional act by the user. Thesystem 10 can rely upon either or both forms of control signal sources12.

Using these configurations, stimulation to achieve continence can beeither unconditional or conditional. Unconditional stimulation isapplied continuously, except when stopped by a manual signal.Conditional stimulation occurs in discrete intervals triggered by amanual or automatic (e.g. neural recoding) signal.

For example, one form of an automatic control signal source 12 cancomprise one or more electrodes 18 to 24 in the array 16 that arepositioned to sense electroneurogram (ENG) activity in the wholepudendal nerve, or in individual efferent external anal sphincter branch(AMB) and/or efferent urethral sphincter branch (UMB). The recording cancomprise a whole nerve recording, with the neural signal recorded beingan aggregate of the activity of all nerve fibers in the pudendal nerve(PNT). However, the whole nerve recording is typically dominated bysignals arising from the largest diameter fibers, which comprise the AMBand UMB. Alternatively, the recording can comprise a selective recordingfrom the individual branches AMB and UMB. Regardless, the recordedactivity is processed by the pulse generator 14 to detect the onset ofhyper-reflexive bladder contractions.

When the onset is detected by the pulse generator 14, a demand input isautomatically transmitted. The pulse generator 14, in turn,automatically generates the desired waveforms to stimulate the afferentgenital sensory branch (GSB)and/or the efferent urethral motor branch(UMB), to thereby arrest the hyper-reflexive contractions and/or affectvoluntary urinary sphincter function, and thereby maintain continence.

One form of a manual control signal source 12 can comprise an externalcontroller 28 that the user manipulates. The external controller cantake the form of a remote control switching device or magnetic reedswitch. The manual controller 28 can be used in the place of or incombination with the ENG sensing electrodes or other form of automaticsignal source 12.

For example, using the manual controller 28, the user can generate acontinence demand input, independent or in the absence of any automaticcontinence demand input. In response, the pulse generator 14 applieselectrical waveforms to the electrode 18 or electrodes 18 to 24 in thearray 16 that are positioned to stimulate the afferent genital sensorybranch (GSB) and/or efferent urethral motor branch (UMB) of the pudendalnerve trunk (PNT). Using the manual controller 28, the user can alsoterminate a continence demand input. As a result, the user is able to“turn on” or “turn off” continence control, depending, e.g., upon thetime of day or fluid consumption. Using a manual controller 28, the usercan also enable or disable an automatic continence demand input source.

As another example, using a manual controller 28, the user can initiatea micturition demand input on their own volition. In response, the pulsegenerator 14 applies electrical waveforms to the electrode 18 orelectrodes 18 to 24 in the array 16 that are positioned to stimulate theafferent urethral sensory branch (USB) and/or the efferent urethralmotor branch (UMB) of the pudendal nerve trunk (PNT). As a result, theuser is able to urinate on demand.

As shown in FIG. 6, the manual controller 28 can be housed in a compact,lightweight, hand held housing 32, which desirable includes its ownmicroprocessor 34 powered by a rechargeable, onboard battery (notshown). The microprocessor 34 carries embedded code which may includepre-programmed rules or algorithms that may govern operation of adisplay 36 and keypad 38, to create a user interface. The microprocessor34 also expresses pre-programmed rules or algorithms under which desireddemand inputs are selected and generated using the display 36 and thekeypad 38. The microprocessor 34 can also have the capability to logdata, and thereby keep a record of detection and stimulation that can beassessed by a physician. Further details of a controller 28 of this typewill be described later.

The basic functional components can be constructed and arranged invarious ways. In one representative implementation, the electrode array16, leads 26, and pulse generator 14 are all implanted. In thisarrangement, the manual controller 28 comprises an external unit thatis, e.g., magnetically coupled to the pulse generator 14, or coupled bya radio frequency link to the pulse generator 14 (e.g., in the manner asdescribed in Peckham et al U.S. Pat. No. 5,167,229, which isincorporated herein by reference). Alternatively, a manual controller 28can be coupled by percutaneous leads to the pulse generator 14.

IV. Lower Bowel Functions

In another embodiment, the system 10 can be configured and operated togenerate and distribute stimulus waveforms selectively to one or moretargeted components of the pudendal nerve trunk (PNT) to control lowerbowel functions.

In one embodiment, the system 10 can be configured and operated tocontrol fecal incontinence. In this arrangement, the system 10 includeat least one electrode 18 sized and configured to be located on, in, ornear a targeted component of the pudendal nerve away from a sacral root.The pulse generator 14 is coupled to the electrode 18 to apply anelectrical signal to stimulate selectively the targeted component. Thetargeted component can comprise an afferent component of the pudendalnerve identified by a clinician to inhibit rectal contractions, or anefferent component identified by a clinician to affect voluntary analsphincter function, or both. The electrode can comprise a singleelectrode 18 or the multiple electrode array 16 of the type shown inFIGS. 3 and 4.

A fecal continence response (arresting contractions of the rectum andaffecting activity of the voluntary anal sphincter) can be evoked byselective stimulation of an afferent component of the pudendal nerve (toinhibit contractions of the rectum), an efferent component of thepudendal nerve (to affect voluntary anal sphincter function), or both.For a fecal continence response, selective stimulation of either or bothafferent or efferent components can be undertaken to affect nerveactivation to evoke the desire physiological responses.

In another embodiment, the system 10 can be configured and operated tocontrol defecation. In this arrangement, the system 10 includes at leastone electrode 18 sized and configured to be located on, in, or near atargeted component of the pudendal nerve away from a sacral root. Thepulse generator 14 is coupled to the electrode 18 to apply an electricalsignal to stimulate selectively the targeted component. The targetedcomponent can comprise an afferent component of the pudendal nerveidentified by a clinician to cause rectal contractions, or an efferentcomponent identified by a clinician to affect voluntary anal sphincterfunction, or both. As before, the electrode can comprise a singleelectrode 18 or the multiple electrode array 16 of the type shown inFIGS. 3 and 4.

A defecation response (increase in contraction of the rectum andreduction in activity in the external anal sphincter) can be evoked byselective stimulation of an afferent component of the pudendal nerve (tocause contractions of the rectum, or affect voluntary anal sphincterfunction, or both), an efferent component of the pudendal nerve (toaffect voluntary anal sphincter function), or both. For a defecationresponse, selective stimulation of an efferent component can beundertaken to affect nerve inactivation, causing relaxation of the analsphincter, thereby facilitating defecation. This may be undertaken aloneor be combined with selective stimulation of an afferent component toaffect nerve activation, causing contraction of the rectum, furtherpromoting defecation. Selective stimulation of an afferent componentalone to affect nerve activation, causing contraction of the rectum, canalso promote defecation.

In either arrangement, single or multiple electrodes may be located on,in, or near the selected afferent branch of the pudendal nerve; or on,in, or near the selected efferent branch of the pudendal nerve; or both.Alternatively, a multiple electrode array 16 may be sized and configuredto be located on, in, or near the pudendal nerve trunk, as FIG. 4 shows.

In this arrangement, to control fecal incontinence, the pulse generator40 is coupled to the electrode array 16 to apply an electrical signal tostimulate selectively the afferent component of the pudendal nerve trunkthat has been identified by the clinician to inhibit rectalcontractions, or an efferent component of the pudendal nerve trunk thathas been identified by the clinician to affect voluntary anal sphincterfunction, or both. Likewise, to control defecation, the pulse generator40 is coupled to the electrode array 16 to apply an electrical signal tostimulate selectively an afferent component of the pudendal nerve trunkthat has been identified by the clinician to cause rectal contractions,or an efferent component of the pudendal nerve trunk that has beenidentified by the clinician to affect voluntary anal sphincter function,or both.

As before explained in connection with the control of lower urinarytract functions, in controlling lower bowel functions, the pulsegenerator 14 can operate to apply the electrical signal in response to avolitional act of an individual. According to the pre-programmed rulesexpressed by the code embedded in the microprocessor 30, the pulsegenerator 14 directs prescribed stimulation waveforms through the leads26 to those electrode or electrodes 18 to 24 in the array 16 thatstimulate the targeted fascicle associated with the desired response,e.g., fecal continence or defecation.

As also previously explained, the system 10 can include at least onerecording electrode located in, on, or near the pudendal nerve or abranch of the pudendal nerve to sense electrical events indicative ofrectal function. In this arrangement, the pulse generator 14 is coupledto the recording electrode and operates to apply the electrical signalin response to the sensed electrical events.

More particularly, the microprocessor code of the pulse generator 14 canexpress rules or algorithms pre-programmed by a clinician, under whichelectroneurogram (ENG) activity in the whole pudendal nerve trunk (PNT),or the individual efferent external anal sphincter branch (AMB) and/orefferent urethral sphincter branch (UMB) of the nerve trunk (PNT), arecharacterized to provide an informational signal. The informationalsignal can relate, e.g., to the state of rectal contraction, rectalvolume, or onset of rectal contraction. The informational signal can beexpressed in a user-readable output, to provide feedback to the user orclinician as to the state of lower bowel function. As will be describedlater, the informational signal can be used as a control, to lead to theautomatic generation of a demand input.

In the illustrated implementation, the pulse generator 14 is programmedto respond to one or more prescribed continence demand inputs to affectan arrest of rectal contractions and/or affect voluntary anal sphincterfunction (thereby achieving continence). In response to the one or moreprescribed continence demand inputs, the pulse generator 14 applieselectrical waveforms to the electrode or electrodes 18 to 24 in thearray 16 that are positioned to stimulate the selected afferentcomponent of the pudendal nerve trunk (PNT)—to inhibit contractions ofthe rectum—and/or the selected efferent component of the pudendal nervetrunk (PNT)—to affect voluntary anal sphincter function.

In the illustrated embodiment, the pulse generator 14 can also beprogrammed to respond to one or more prescribed defecation demand inputsto affect defecation. In response to the one or more prescribeddefecation demand inputs, the pulse generator 14 applies electricalwaveforms to the electrode or electrodes 18 to 24 in the array 16 thatare positioned to stimulate the selected afferent component of thepudendal nerve trunk (PNT)—to cause rectal contractions—and/or theselected efferent component of the pudendal nerve trunk (PNT)—to affectvoluntary anal sphincter function.

A given control signal source 12 can be configured to generate thedemand inputs automatically, without volitional act by the user. A givencontrol signal source 12 can also be configured to generate the demandinputs manually, thereby requiring a volitional act by the user. Thesystem 10 can rely upon either or both forms of control signal sources12.

Using these configurations, stimulation to achieve continence can beeither unconditional or conditional. Unconditional stimulation isapplied continuously, except when stopped by a manual signal.Conditional stimulation occurs in discrete intervals triggered by amanual or automatic (e.g. neural recoding) signal.

For example, as previously described, one form of an automatic controlsignal source 12 can comprise one or more electrodes 18 to 24 in thearray 16 that are positioned to sense electroneurogram (ENG) activity inthe whole pudendal nerve, or in individual efferent external analsphincter branch (AMB) and/or efferent urethral sphincter branch (UMB).The recorded activity is processed by the pulse generator 14 to detectthe onset of rectal contractions.

When the onset is detected by the pulse generator 14, a demand input isautomatically transmitted. The pulse generator 14, in turn,automatically generates the desired waveforms to stimulate the afferentcomponent and/or the efferent component, to thereby arrest thecontractions and/or affect voluntary anal sphincter function, andthereby maintain fecal continence.

One form of a manual control signal source 12 can comprise the externalcontroller 28 that the user manipulates. The external controller cantake the form of a remote control switching device or magnetic reedswitch. The manual controller 28 can be used in the place of or incombination with the ENG sensing electrodes or other form of automaticsignal source 12.

For example, using the manual controller 28, the user can generate afecal continence demand input, independent or in the absence of anyautomatic fecal continence demand input. In response, the pulsegenerator 14 applies electrical waveforms to the electrode or electrodes18 to 24 in the array 16 that are positioned to stimulate the selectedafferent component and/or the selected efferent component of thepudendal nerve trunk (PNT). Using the manual controller 28, the user canalso terminate a fecal continence demand input. As a result, the user isable to “turn on” or “turn off” fecal continence control, depending,e.g., upon the time of day or food consumption. Using a manualcontroller 28, the user can also enable or disable an automatic fecalcontinence demand input source.

As another example, using the manual controller 28, the user caninitiate a defecation demand input on their own volition. In response,the pulse generator 14 applies electrical waveforms to the electrode orelectrodes 18 to 24 in the array 16 that are positioned to stimulate theselected afferent component and/or the selected efferent component ofthe pudendal nerve trunk (PNT). As a result, the user is able todefecate on demand.

In an alternative embodiment, the system 10 can be configured andoperated to control peristalsis. In this arrangement, the system 10include at least one electrode 18 sized and configured to be located on,in, or near a targeted component of the pudendal nerve away from asacral root. The pulse generator 14 is coupled to the electrode 18 toapply an electrical signal to stimulate selectively a targeted afferentcomponent of the pudendal nerve identified by a clinician to controlperistalsis. The electrode 18 can comprise a single electrode or themultiple electrode array of the type shown in FIGS. 3 and 4. Theelectrode can be located on, in, or near an afferent branch of thepudendal nerve. Alternatively, the electrode can be located on, in, ornear the pudendal nerve trunk. In this arrangement, the pulse generator14 serves to stimulate selectively the identified afferent component inthe pudendal nerve trunk. As with other lower bowel control functions,the pulse generator 14 can operate to apply the electrical signal inresponse to a volitional act of an individual. According to thepre-programmed rules expressed by the code embedded in themicroprocessor 30, the pulse generator 14 directs prescribed stimulationwaveforms through the leads 26 to those electrode or electrodes 18 to 24in the array 16 that stimulate the targeted fascicle associated with thedesired peristalsis control response. As also previously explained, thesystem 10 can include at least one recording electrode located in, on,or near the pudendal nerve or a branch of the pudendal nerve to senseelectrical events indicative of peristalsis function. In thisarrangement, the pulse generator 14 is coupled to the recordingelectrode and operates to apply the electrical signal in response to thesensed electrical events.

A response for controlling peristalsis (contraction of the colon) can beevoked by selective stimulation of one or more afferent components ofthe pudendal nerve. For peristalsis, selective stimulation of either orboth afferent or efferent components can be undertaken to affect nerveactivation to evoke the desire physiological responses.

As shown in FIG. 6, the manual controller 28 for lower bowel control canalso be housed in a compact, lightweight, hand held housing 32, whichdesirable includes its own microprocessor 34 powered by a rechargeable,onboard battery (not shown). Additional features of the controller 28when used for lower urinary tract control functions can also be used toachieve lower bowel control functions.

As with lower urinary tract control functions, the basic functionalcomponents for lower bowel control functions can be constructed andarranged in various ways. In one representative implementation, theelectrode array 16, leads 26, and pulse generator 14 are all implanted.In this arrangement, the manual controller 28 comprises an external unitthat is, e.g., magnetically coupled to the pulse generator 14, orcoupled by a radio frequency link to the pulse generator 14 (e.g., inthe manner as described in Peckham et al U.S. Pat. No. 5,167,229, whichis incorporated herein by reference). Alternatively, a manual controller28 can be coupled by percutaneous leads to the pulse generator 14.

V. Control of Sexual Functions

In another embodiment, the system 10 can be configured and operated togenerate and distribute stimulus waveforms selectively to one or morecomponents of the pudendal nerve trunk (PNT) to control sexualfunctions, such as—in males—erection, ejaculation, or orgasm, and—infemales—vaginal lubrication or orgasm.

In one embodiment, the system 10 can be configured and operated tocontrol erection in males and vaginal lubrication in females. In thisarrangement, the system 10 include at least one electrode 18 sized andconfigured to be located on, in, or near a targeted component of thepudendal nerve away from a sacral root. The pulse generator 14 iscoupled to the electrode 18 to apply an electrical signal to stimulateselectively the targeted component. The targeted component can comprisean afferent component of the pudendal nerve, which is identified by aclinician to dilate blood vessels and cause erection in a male, or leadto vaginal lubrication in a female, alone or in combination with otherafferent components of the nervous system (e.g., ventral genital) and/orother efferent components of the nervous system.

In another embodiment, the system 10 can be configured and operated tocontrol ejaculation in males. In this arrangement, the system 10 includeat least one electrode 18 sized and configured to be located on, in, ornear a targeted component of the pudendal nerve away from a sacral root.The pulse generator 14 is coupled to the electrode 18 to apply anelectrical signal to stimulate selectively the targeted component. Thetargeted component can comprise an afferent component of the pudendalnerve, or an efferent component of the pudendal nerve, or both, whichare identified by a clinician to contract pelvic muscles and causeejaculation, alone or in combination with other afferent components ofthe nervous system (e.g., ventral genital) and/or other efferentcomponents of the nervous system.

In another embodiment, the system 10 can be configured and operated tocontrol orgasm in males or females. In this arrangement, the system 10include at least one electrode 18 sized and configured to be located on,in, or near a targeted component of the pudendal nerve away from asacral root. The pulse generator 14 is coupled to the electrode 18 toapply an electrical signal to stimulate selectively the targetedcomponent. The targeted component can comprise one or more afferentcomponents of the pudendal nerve which are identified by a clinician toevoke orgasm in an individual, alone or in combination with otherafferent components of the nervous system (e.g., ventral genital) andother components of the nervous system.

In any of these embodiments, the electrode 18 can comprise a singleelectrode or the multiple electrode array 16 of the type shown in FIGS.3 and 4. The single or multiple electrodes may be located on, in, ornear the selected afferent branch of the pudendal nerve; or on, in, ornear the selected efferent branch of the pudendal nerve; or both.Alternatively, a multiple electrode array 16 may be sized and configuredto be located on, in, or near the pudendal nerve trunk, as FIG. 4 shows.

In this arrangement, the pulse generator 40 is coupled to the electrodearray 16 to apply an electrical signal to stimulate selectively theselected afferent and/or efferent components of the pudendal nervetrunk.

As before explained in connection with the control of lower urinarytract functions, in controlling sexual functions, the pulse generator 14can operate to apply the electrical signal in response to a volitionalact of an individual. According to the pre-programmed rules expressed bythe code embedded in the microprocessor 30, the pulse generator 14directs prescribed stimulation waveforms through the leads 26 to thoseelectrode or electrodes 18 to 24 in the array 16 that stimulate thetargeted fascicle associated with the desired sexual response.

As shown in FIG. 6, the manual controller 28 for sexual controlfunctions can also be housed in a compact, lightweight, hand heldhousing 32, which desirable includes its own microprocessor 34 poweredby a rechargeable, onboard battery (not shown). Additional features ofthe controller 28 when used for lower urinary tract control functionscan also be used to achieve sexual control functions.

As with lower urinary tract control functions, the basic functionalcomponents for sexual control functions can be constructed and arrangedin various ways. In one representative implementation, the electrodearray 16, leads 26, and pulse generator 14 are all implanted. In thisarrangement, the manual controller 28 comprises an external unit thatis, e.g., magnetically coupled to the pulse generator 14, or coupled bya radio frequency link to the pulse generator 14 (e.g., in the manner asdescribed in Peckham et al U.S. Pat. No. 5,167,229, which isincorporated herein by reference). Alternatively, a manual controller 28can be coupled by percutaneous leads to the pulse generator 14.

VI. Programming the Pulse Generator

In achieving any of the foregoing control functions, the pulse generator14 can be linked to a remote computer for programming by a clinician.The programming allows a clinician to customize or “tune” the coderesiding in the microprocessor 30 of the pulse generator 14 accordingthe specific needs of the user, the treatment goals of the clinician,and the particular anatomy of the pudendal nerve trunk associated withthe electrode array 16.

A primary purpose of the programming is to adjust and store the locationand operating parameters affecting the selection of electrodes 18, 20,22, and 24 to perform the intended recording and/or targeted stimulationfunctions. During programming, logged data stored by the controller 28can also be downloaded for assessment. The programming assesses whichelectrode or electrodes 18, 20, 22, and 24 are best positioned withrespect to the various fascicles of the nerve branches in the pudendalnerve trunk (PNT), along with the operating parameters for eachelectrode 18, 20, 22, and 24, to affect the desired targeted degree ofneural recording and/or neural stimulation for continence control ormicturition control.

The programming maps the relative position of the implanted electrodes18, 20, 22, and 24 with respect to the selected afferent and/or efferentcomponents of the particular pudendal nerve trunk (PNT). With respect toeach selected component, the programming refines the selected electrodeor electrodes in terms of location and operating parameters, to obtainthe desired, targeted stimulation result, as well as the desired,targeted neural recording, when desired. As before explained, wholenerve recording/stimulation can also be used.

The programming also determines the nature and character ofelectroneurogram (ENG) activity in pudendal nerve or the efferentexternal anal sphincter branch (AMB) and/or efferent urethral sphincterbranch (UMB) that correspond with the onset of hyper-reflexive bladdercontractions.

VII. Treatment Protocols and Choice

Another primary purpose of the programming is to install therapy ortreatment protocols for the individual user. The treatment protocolsestablish the various physiological function demand inputs and theresponding stimulation waveforms and their operating parameters anddistribution. The treatment protocols also establish the automatic ormanual nature of the various continence and micturition demand inputs.

When a programmable manual controller 28 of the type shown in FIG. 6 isused, the programming can also establish interaction between the manualcontroller 28 and the pulse generator 14. By programming the controller28 and the pulse generator 14, the user can be provided with the abilityto more closely control the operation of controller 28 and the pulsegenerator 14. By programming the controller 28 and the pulse generator14, the user can be given the ability to select and modify operatingparameters affecting his/her day-to-day life.

For example, the controller 28 can be programmed to list on the display36 a menu 40 of choices (see FIG. 7). By operation of the keypad 38, theuser can select Urinate. The selection generates the appropriatemicturition demand input to the pulse generator 14 and results inbladder evacuation.

By operation of the keypad 38, the user can select Continence Auto Mode(On). The selection generates the appropriate input to the pulsegenerator 14 to enable the automatic generation of a continence demandinput based upon neural sensing and results in automatic continuouscontinence maintenance.

By operation of the keypad 38, the user can select Continence Auto Mode(Off). The selection generates the appropriate input to the pulsegenerator 14 to disable the automatic generation of a continence demandinput based upon neural sensing. By selecting Steady State ContinenceControl, the pulse generator 14 receives an appropriate continuouscontinence demand input. In response, the pulse generator 14 appliescontinuous stimulation. The result is manually controlled continuouscontinence maintenance.

With Continence Auto Mode (Off) selected, the user can also selectCyclical Continence Control. In response, the pulse generator 14receives an appropriate cyclical continence demand input. The pulsegenerator 14 applies a cyclical stimulation waveform that, e.g., applieslittle or no stimulation at the outset of the stimulation period, butthen increases the magnitude of the stimulation over time until aprescribed maximum degree of stimulation is achieved. The result isminimal continence maintenance at the outset (i.e., immediately afterbladder evacuation), with an increasing degree of continence maintenancewith the passage of time (as the bladder fills), until maximum degree ofcontinence maintenance is achieved at or near the time when micturitionis indicated. At this time, the user can select Urinate, and restart thecyclical stimulation waveform.

With Continence Auto Mode (Off) selected, the user can also selectContinence Control (Off). In response, the pulse generator 14 receivesno continence demand input. By subsequently selecting Steady StateContinence Control or Cyclical Continence Control or Auto ContinenceMode (On), the user can restart stimulation to affect continence.

As the following Table demonstrates, the system 10 may be configured andprogrammed to achieve diverse selective stimulation objectives involvingnerve fascicles in the pudendal nerve trunk (PNT) or its branches, aswell as other mixed or compound nerves within the body. Selectivityamong nerve components can include the selection among the componentswithin a compound nerve trunk, or among branches of a nerve trunk, orbetween afferent (sensory) or efferent (motor) nerve fibers with a givennerve structure, or selection with regard to size of nerve fibers, orwith regard to direction of activation, or with regard to the functionsof nerve activation (resulting in the generation of an action potentialor impulse and its propagation along a nerve) or nerve inactivation orblock (resulting in prevention of activation or propagation of an actionpotential or impulse).

Other nerve branches not specifically listed can also be recorded and/orstimulated to achieve desired therapeutic objectives.

TABLE Representative Configuration and Operation of the System Involvingthe Pudendal Nerve Trunk or its Branches to Achieve DifferentPhysiological Responses Selective Stimulation Control Afferent EfferentSystem Function Process Component Component Lower ContinenceRelax/Inhibit X Urinary Bladder (RI/RA) Tract Contract Exterior X XVoluntary Urinary (RA) (DA) Sphincter Contract Interior X (NotVoluntary) (RA) Urinary Sphincter Lower Micturition Contract Bladder XUrinary (RA) Tract Relax Exterior X X Voluntary Urinary (RI) (DI)Sphincter Relax Interior X (Not Voluntary) (RI) Urinary Sphincter LowerContinence Relax/Inhibit X Bowel Rectum (RI/RA) Contract Exterior X XVoluntary Anal (RA) (DA) Sphincter Contract Interior X (Not Voluntary)(RA) Anal Sphincter Lower Defecation Contract Rectum X Bowel (RA) RelaxExterior X X Voluntary Anal (RI) (DI) Sphincter Relax Interior X (NotVoluntary) (RI) Anal Sphincter Lower Peristalsis Contract Colon X XBowel (RA) (DA) Sexual Erection Dilate Blood X Vessels (RA) SexualVaginal Cause Lubrication X Lubrication (RA) Sexual Ejaculation ContractPelvic X X Muscles (RA) (DA) Sexual Orgasm Central Nervous X System (RA)Notes: RA identifies reflex activation by stimulation of pudendalsensory nerve component(s), whereby control is achieved by activation ofneural circuits in the central nervous system. RI identifies reflexinhibition by stimulation of pudendal sensory nerve component (s),whereby control is achieved by inhibition of neural circuits in thecentral nervous system. DA identifies direct activation by stimulationof pudendal motor nerve component(s), whereby control is achieved byactivation of muscles (e.g., contraction of a sphincter) DI identifiesdirect inactivation or block by stimulation of pudendal motor nervecomponent(s), whereby control is achieved by inactivation of muscles(e.g., relaxation of a sphincter)

Various features of the invention are set forth in the following claims.

1. A method comprising: identifying at least one desired physiologicfunction selected from the group consisting essentially of controllingurinary incontinence, controlling micturition, controlling fecalincontinence, controlling defecation, controlling peristalsis,controlling erection, controlling vaginal lubrication, controllingejaculation, and controlling orgasm, providing an array of spaced apartelectrodes, providing an electrical pulse generator that includes aprogrammable microprocessor carrying embedded code, placing the arrayon, in, or near a pudendal nerve trunk away from a sacral root, thepudendal nerve trunk comprising afferent and efferent nerve components,coupling a lead to connect the array to the electrical pulse generatorat a location remote from the array, tuning the array by programming theembedded code in the microprocessor, said tuning comprising (i) mappingrelative portion of targeted electrode or electrodes in the array withrespect to the afferent and/or efferent components of the pudendal nervetrunk that, when selectively stimulated, affect the desired physiologicfunction and (ii) defining operating parameters for the targetedelectrode or electrodes to achieve the selective stimulation, and aftertuning the array, electrically stimulating the pudendal nerve trunk,said stimulation comprising enabling operation of the electrical pulsegenerator to transmit to the targeted electrode or electrodes electricalstimulation waveforms having the defined operating parameters to achievethe selectively stimulation to affect the desired physiologic function.2. A method according to claim 1 wherein at least two desiredphysiologic functions are identified, and wherein the array is tuned toaffect all identified physiologic functions on a selective basis.
 3. Amethod according to claim 1 wherein the desired physiologic functionselected comprises controlling urinary incontinence, and wherein thearray is tuned to stimulate an afferent genital component, or anefferent urethral component, or both.
 4. A method according to claim 1wherein the desired physiologic function selected comprises controllingmicturition, and wherein the array is tuned to stimulate an afferenturethral component, or an efferent urethral component, or both.
 5. Amethod according to claim 1 wherein the desired physiologic functionsselected comprises controlling urinary incontinence and controllingmicturition, and wherein the array is tuned to operate in a first modeto stimulate an afferent genital component, or an efferent urethralcomponent, or both to affect control of urinary incontinence and tooperate in a second mode to stimulate an afferent urethral component, oran efferent urethral component, or both to affect control ofmicturition.
 6. A method according to claim 1 wherein the electricalpulse generator is enabled in response to a volitional act of anindividual.
 7. A method according to claim 1 further including placingat least one recoding electrode on, in, or near a nerve to senseelectrical events, and wherein the electrical pulse generator is enabledin response to the sensed electrical events.
 8. A method according toclaim 1 wherein the array, electrical pulse generator, and the lead areimplanted.